1. Field of the Invention
The present invention relates to a vehicle generator mounted on a vehicle such as a passenger car or a truck.
2. Description of Related Art
There is known a vehicle alternating-current generator provided with a three-phase full-wave rectifier constituted of power MOS transistors to improve power generation performance. For example, refer to Japanese Patent Application Laid-Open No. H8-336259. In the above vehicle generator, gate control voltages for on/off-controlling six power MOS transistors constituting the three-phase full-wave rectifier are generated by a controller.
However, the conventional vehicle generator as described in the above patent document has a problem in that since all the power MOS transistors constituting the three-phase full-wave rectifier are on/off-controlled by the same controller, if this controller malfunctions, the three-phase full-wave rectifier stops functioning. It might occur to adopt a configuration in which the power MOS transistors constituting the three-phase full-wave rectifier are grouped into each of the phases of the stator winding, and the controller is provided for each group so that even when one of the controllers provided for a corresponding one of the groups malfunctions, the vehicle generator can continue to perform a partial power generating operation using the other controllers. However, such a configuration is difficult to implement because since it is difficult for the controllers to cooperate with one another, it is difficult to control the phase current of the vehicle generator as a whole, and to locate a fault in the phases of the vehicle generator.